1. are literary figures of speech usually composed of a pair of neighbouring contradictory words.

2. Jombo Shrimp, free love, only choice, even odds, pretty ugly, living dead, freezer burn, rolling stop , found missing, and larger half.

3. a oxymoron is a combination of contradictory or incongruous words. a contradiction is a difference in two of more statment, ideas, stories, etc that makes it impossible for both or all of them to be true.

4.beacon light of hope, flames of withering injustice, joyous daybreak, long night of their captivity, crippled by the manacles of sugregation and the chains of discrimination, island of poverty, vest ocean of material prosperity, to cash a check, architects of our republic, signing a promissory note, to fall heir, note, defaulted on this promissory note, bad check; a check which has come back marked "insufficient funds, insufficient funds in the great vaults of opportunity of this nation, cash this check, a check that will give us upon demand the richesof freedom and the security of justice, tranquilizing drug of gradualism, dark and desolate valley of sugregation,
sunlight path of racial justice, quicksands of racial injustice, solid rock of brotherhood, sweltering summer of the Negro's legtimate discontent, invigorating autumn of freedom and equality, whirlwinds of revolt, foundations of our nation, bright day of justice, who stand on the warm thereshold which leads into the palace of justice, saftey our thirst for freedom by drinking from the cup of bitterness and hatred, [desert] state sweltering with the heat of injustice, sweltering with the heat of oppression, oasis of freedom and justice, hew out of the mountian of despair a stone of hope, jangling discords of our nation into a beautiful symphony of brotherhood.
http://www.wfu.edu/~zulick/341/king.html
Margaret D. Zulick
www.fun-with-words.com/oxym_explain.html

http://www.merriam-webster.com/dictionary/contradiction